1. Field of the Invention
The present invention relates to a transfer-section contamination prevention device and an image forming apparatus.
2. Description of Related Art
In general, an electrophotographic image forming apparatus (such as a printer, a copy machine, and a fax machine) is configured to irradiate (expose) a charged photoconductor with (to) laser light based on image data to form an electrostatic latent image on the surface of the photoconductor. The electrostatic latent image is then visualized by supplying toner from a developing device to the photoconductor (image carrier) on which the electrostatic latent image is formed, whereby a toner image is formed. Further, the toner image is directly or indirectly transferred to the sheet, and thereafter fixed through heating and pressing at a fixing nip of a heating member (for example, a fixing roller) and a pressing member (for example, a pressure roller), thereby forming an image on the sheet.
Conventionally, image formation systems have been practically used in which a sheet feeding apparatus that feeds a continuous sheet such as continuous roll paper and folded paper is connected at the preceding side of the image forming apparatus, and a winding apparatus that winds up the sheet on which an image has been formed by the image forming apparatus is connected at the succeeding side of the image forming apparatus.
Examples of the sheets used in the above-mentioned image formation system include, in addition to common sheets composed only of paper, a sheet called label sheet which contains paste (adhesive agent) for pasting. Examples of such a label sheet include, in addition to short sheets such as A4-sheets, rolled long sheets of several hundred meters long in one roll (hereinafter referred to as “label roll sheet”).
Meanwhile, when a label sheet containing adhesive agent is used in the above-mentioned image formation system, the adhesive agent of an end portion of the label sheet may possibly leak with pressure exerted on the sheet at the time of transferring a toner image on the label sheet or at the time of fixation after transfer of a toner image. If the leaked adhesive agent adheres on the movable section (transfer section) including the transfer belt and the transfer roller, cleaning defects and image defects may possibly be caused.
As a device for removing foreign matters adhered on the surface of a photoconductor, Japanese Patent Application Laid-Open No. 6-230727 discloses a photoconductor cleaning device, for example. The photoconductor cleaning device includes a cleaning blade configured to peel and remove foreign matters adhered on the surface of the photoconductor, and the contact angle and the pressing linear load of the cleaning blade to the photoconductor surface are set for the purpose of removing the foreign matters adhered on the surface of the photoconductor.
In the photoconductor cleaning device disclosed in Japanese Patent Application Laid-Open No. 6-230727; however, when the foreign matter adhered on the surface of the photoconductor is adhesive agent leaked from a label sheet containing the adhesive agent for example, the adhesive agent having adhesiveness may not be surely removed from the surface of the photoconductor, and the remaining adhesive agent may transfer to a transfer section, thus causing cleaning defects and image defects.